Keywords
constructed wetlands, enviromental decision support system, evaluation process, validation, verification
Start Date
1-7-2006 12:00 AM
Abstract
Daily operation and maintenance tasks are needed to guarantee the correct performance of Constructed Wetlands (CWs). The definition of these activities is a complex task since these actions vary according to the technology, the configuration and the design of the wastewater treatment plant, the community characteristics and the features of the receiving media. To support the definition of these actions an Environmental Decision Support System (EDSS) has been constructed (EDSS-maintenance). The methodology used to develop EDSS-maintenance is based on the following 5 steps: environmental problem analysis, data and knowledge acquisition, model selection, model implementation and validation. The first 4 steps have been finished: the required data and knowledge to solve the environmental problem were acquired and translated into a knowledge base composed of IF THEN rules. The validation process is ongoing and there are no clear guidelines on EDSS validation, on the contrary, it is still an open problem. This document presents a new approach for this step. The validation process has to guarantee both the functioning of the EDSS-maintenance and the compliance with the user requirement specifications: identify the CWs problems, identify the causes unleashing these disturbances and propose the most appropriate corrective actions. The validation procedure is done in several stages: checking the syntax and the semantic of the rules (Validation-1 step), comparing the tasks proposed by the EDSS-maintenance with real operation and maintenance protocols (Validation-2 step), expert evaluation of guidelines proposed by the EDSS-maintenance (Validation-3 step), and evaluating the results of the application of operation and maintenance protocols in new CWs (Validation-4 step). Two numerical indices allow verification of the EDSS-maintenance performance and the checking of the compliance of the protocols with the user requirements. Moreover, another index enables an easy revision and improvement of the knowledge bases (problems, causes and actions) and so enhance the decision support system.
Confronting EDSS-maintenance validation
Daily operation and maintenance tasks are needed to guarantee the correct performance of Constructed Wetlands (CWs). The definition of these activities is a complex task since these actions vary according to the technology, the configuration and the design of the wastewater treatment plant, the community characteristics and the features of the receiving media. To support the definition of these actions an Environmental Decision Support System (EDSS) has been constructed (EDSS-maintenance). The methodology used to develop EDSS-maintenance is based on the following 5 steps: environmental problem analysis, data and knowledge acquisition, model selection, model implementation and validation. The first 4 steps have been finished: the required data and knowledge to solve the environmental problem were acquired and translated into a knowledge base composed of IF THEN rules. The validation process is ongoing and there are no clear guidelines on EDSS validation, on the contrary, it is still an open problem. This document presents a new approach for this step. The validation process has to guarantee both the functioning of the EDSS-maintenance and the compliance with the user requirement specifications: identify the CWs problems, identify the causes unleashing these disturbances and propose the most appropriate corrective actions. The validation procedure is done in several stages: checking the syntax and the semantic of the rules (Validation-1 step), comparing the tasks proposed by the EDSS-maintenance with real operation and maintenance protocols (Validation-2 step), expert evaluation of guidelines proposed by the EDSS-maintenance (Validation-3 step), and evaluating the results of the application of operation and maintenance protocols in new CWs (Validation-4 step). Two numerical indices allow verification of the EDSS-maintenance performance and the checking of the compliance of the protocols with the user requirements. Moreover, another index enables an easy revision and improvement of the knowledge bases (problems, causes and actions) and so enhance the decision support system.
